Well tool

Abstract

A ported sliding sleeve valve for use in a well tubing to provide a lateral flow path for transfer of fluids between the tubing and the annulus exterior thereof, the lateral ports of the device being initially closed by a port closure sleeve which is movable to port-opening position by increasing the annulus pressure to a level exceeding tubing pressure by a predetermined value, the port closure sleeve moving to fully open position upon being released and afterwards remaining in this position while the lateral ports of the device are thereafter opened and closed by shifting a built-in sliding sleeve valve through use of a shifting tool run and operated via wireline or pumpdown tools in a manner well known in the industry.

I claim: 
     
       1. A well tool, comprising: a. an elongate tubular body having means on its opposite ends for attachment to a well flow conductor and having lateral port means intermediate its ends fluidly communicating its interior with the exterior thereof;   b. first sleeve valve means in said tubular body slidable between positions opening and closing said lateral port means;   c. second sleeve valve means in said tubular body surrounding said first sleeve means and initially closing said lateral port means, said second sleeve valve means being movable to a position opening said lateral port means in response to a predetermined high pressure from exterior of said tubular body; and   d. seal means initially sealingly engaged between said tubular body and said second sleeve valve means to prevent leakage of fluids between the interior and exterior of said body through said lateral port means.   
     
     
       2. The device of claim 1, including releasable means retaining said second sleeve in initial closed position, said releasable means releasing said second sleeve valve means for movement to open position when pressure exterior thereof reaches a predetermined high value. 
     
     
       3. The device of claim 2, wherein said means retaining said second sleeve valve in initial closed position is at least one frangible member engaged between said second sleeve valve and said tubular body, said frangible member fracturing and releasing said second sleeve valve means for movement to open position when the pressure exterior thereof reaches a predetermined value. 
     
     
       4. The device of claim 3, wherein said at least one frangible member is a shear screw threaded into one and having a portion thereof engageable in recess means on the other of said tubular body and said second sleeve valve means. 
     
     
       5. The device of claim 1, 2, 3, or 4, wherein said seal means for sealing between said tubular body and said sleeve valve include: a. first seal means sealing between said tubular body and said second sleeve valve means on one side of said lateral port means and spaced longitudinally therefrom; and   b. second seal means sealing between said tubular body and said second sleeve valve means on the opposite side of said lateral port means and spaced longitudinally therefrom, said second seal means sealing an area larger than that area sealed by said first seal means, the difference between these two areas being subjected to pressures interior of the tubing and exterior thereof, the force resulting from the difference in these pressures acting on the difference in these areas becoming effective to move said second sleeve valve means to open position when said pressure exterior of said tubing exceeds said pressure within said tubing by a predetermined value.   
     
     
       6. The device of claim 5, wherein: a. said first seal means is carried in said tubular body and is initially engaged with a seal surface provided on the exterior of said second sleeve valve means; and   b. said second seal means is carried on said second sleeve valve means and is initially engaged with a seal surface formed in said tubular body.   
     
     
       7. The device of claim 6, including: a. internal shoulder means in said tubular body;   b. abutment means on said second sleeve valve means; and   c. biasing means engaged between said shoulder means in said body and said abutment means on said second sleeve valve means to aid in moving said second sleeve valve means to open position.   
     
     
       8. The device of claim 7, wherein said second sleeve valve means is held in open position by said biasing means after it has been moved to open position. 
     
     
       9. The device of claim 8, wherein said biasing means is a coil spring.